JP2002231496A - X-ray high voltage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive X-ray high voltage device capable of coping even with pulse X-ray output while reducing a space by miniaturizing a high voltage switch, and incorporating a grid control circuit. SOLUTION: This X-ray high voltage device includes a high voltage generating means for generating high voltage, a plurality of X-ray tubes for exposing an X-ray on the basis of high voltage output in the high voltage generating means, a plurality of filament heating transformers respectively arranged with respective plural X-ray tubes, and respectively heating the respective X-ray tubes, a first switching means for switching the high voltage output with respective plural X-ray tubes, and a second switching means arranged on the primary side of the plurality of filament heating transformers, and switching the plurality of respective filament heating transformers according to switching of the first switching means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray high voltage device used for diagnostic X-ray devices and the like, and more particularly to an X-ray high voltage device for supplying a high voltage to an X-ray tube having a grid as a control electrode. About.

[0002]

2. Description of the Related Art As this kind of X-ray high-voltage apparatus, for example, there is an apparatus as shown in FIG. FIG. 5 is a circuit diagram showing the configuration of this conventional example.

In FIG. 5, an X-ray high voltage device 301 is
A commercial AC power supply 3, a rectifying and smoothing circuit (AC / DC) 5 for rectifying and smoothing the commercial AC power supply 3 and outputting a DC voltage, and an inverter circuit (DC / AC) for converting the DC voltage to an AC voltage
7. A high-voltage transformer 9 for converting an AC voltage into a predetermined high voltage, and high-voltage rectifier circuits 11a and 11 for rectifying a high AC voltage.
b, an X-ray tube 13 having an anode A and a cathode K, a filament heating transformer 21, a filament heating circuit 19 for exciting the filament heating transformer 21 to heat the filament of the X-ray tube 13, and an inverter circuit 7 based on signals a and b. A control circuit 17 for controlling the filament heating circuit 19 is provided.

First, an AC voltage supplied from an AC power supply 3 or the like is converted into DC by a rectifying / smoothing circuit 5 and then input to an inverter circuit 7.

When the inverter circuit 7 starts operating according to the signal a of the control circuit 17, the DC voltage input to the inverter circuit 7 is converted into an AC voltage and input to the primary winding of the high-voltage transformer 9. The AC voltage boosted by the high-voltage transformer 9 is output from the secondary winding, and the high-voltage rectifier circuit 11
A positive high voltage is obtained on the a side, and a negative high voltage is obtained on the high voltage rectifier circuit 11b side. Each of these DC voltages is smoothed by the stray capacitances 15a and 15b of the high voltage cable and applied to the anode A and the cathode K of the X-ray tube 13.

On the other hand, when the filament heating circuit 19 operates based on the signal b of the control circuit 17, the filament heating circuit 19 generates an AC voltage to excite the primary winding of the filament heating transformer 21. Due to the AC voltage induced on the secondary side of the filament heating transformer 21, a current flows through the filament arranged on the cathode side of the X-ray tube 8, and thermoelectrons are emitted from the filament.

The X-ray tube 1 with the filament heated
When a high voltage is applied between the anode A and the cathode K of No. 3, thermions emitted from the filament are accelerated at a high voltage, and generate a braking X-ray when colliding with the anode.

Next, when the operation of the inverter circuit 7 stops, the secondary voltage of the high-voltage transformer 9 becomes zero.
The current stops flowing between the anode A and the cathode K of the wire tube 13, and the X-ray irradiation stops.

As described above, by starting / stopping the inverter circuit 7, the current of the X-ray tube 13 can be turned on / off.

Incidentally, in a general-purpose X-ray high-voltage device, one X-ray tube has two filaments, and one X-ray high-voltage device has two X-ray tubes (two tubes) or three X-ray tubes. This connection is generally used.

FIG. 6 shows an X with two filaments.
There is disclosed an example of a conventional X-ray high voltage device to which two wire tubes can be connected. Note that parts that are the same as in FIG. 5 are given the same reference numerals. In the following, the operation of FIG. 6 that is different from that of FIG. 5 will be described.

The X-ray high voltage device 401 shown in FIG. 6 has an anode A and a cathode K (common C) as compared with the configuration shown in FIG.
・ Two X-ray tubes 14 including large L and small S)
a, 14b, and high-pressure switches 30a, 30b for selecting the X-ray tubes 14a, 14b. further,
The output of the filament heating circuit 23 is connected to two filament heating transformers 21a and 21b.

The high-voltage switching device 30a is provided so as to correspond to one contact on the anode side of the X-ray tube 12a and each terminal of the common C, large L and small S on the cathode side of the X-ray tube 12a. And a contact.

In the X-ray high-voltage device 401 having such a configuration, when one of the high-voltage switches 30a and 30b is turned off, the high-voltage DC voltage rectified by the high-voltage rectifier circuits 11a and 11b becomes two. It is distributed to X-ray tubes 14a and 14b.

When the high-voltage switch 30a is closed, the voltages rectified by the high-voltage rectifier circuits 11a and 11b are smoothed by the floating capacitors 15a and 15b of the high-voltage cable, and the X-ray tube 1
4a is applied between the anode A and the cathode common C (common). Then, based on the signal b of the control circuit 17,
When the filament heating circuit 23 operates, the filament heating transformers 21a and 21b are excited, and the AC voltage induced in the secondary coil of the transformer heats the filament of the X-ray tube 14a via the high voltage switch 25a.

Similarly, when the high voltage switch 30b is closed, the rectified voltage is applied to the stray capacitance 15 of the high voltage cable.
c, 15d, anode A of X-ray tube 14b
And the common C of the cathode. Then, based on the signal b of the control circuit 17, X through the high voltage switch 25b.
The filament of the wire tube 14b is heated.

Thus, the X-ray tubes 14a and 14b can be switched by turning on and off the high voltage switches 30a and 30b.

FIGS. 7A and 7B show the structure of a high-voltage switch used in such an X-ray high-voltage device. FIG. 7 (A)
As shown in (B), the high-voltage switcher 501 can contact a plurality of high-voltage sockets 502, fixed contacts 505 protruding below the high-voltage sockets 502, and the fixed contacts 505 by, for example, a solenoid. Movable contact 504
And a support member 503 for supporting each of the high-pressure sockets 502 and the solenoid. Then, the X-ray tube is connected to the X-ray high-voltage device using the high-voltage cable, the high-voltage socket 502, and the plug.

[0019]

By the way, in the conventional X-ray high-voltage apparatus having a plurality of X-ray tubes as described above, the number of contacts in the high-voltage switch for selecting one of the X-ray tubes is limited. The anode side may have only one contact, but since the cathode side of the X-ray tube has three terminals of common C, large L and small S, three convenient contacts are required.

The output of the filament heating transformer is a low voltage / high current load (for example, 3 to 20 V, 1.5
6A), it is necessary to increase the contact pressure and reduce the contact resistance. Therefore, the opening and closing of a low voltage and a large current requires a large contact point, and the high voltage switch becomes a mechanically large device.

Further, in the X-ray high-voltage apparatus, since a high voltage is generally used, electric discharge occurs when another member approaches the vicinity of the exposed end of the movable contact shown in FIG. Therefore, in such a switch, a space must be ensured so that another member does not approach or exist in a predetermined space around the movable contact.

In particular, in addition to the switch itself being large,
In order to secure the space, the occupied area required to form the contact has an area that occupies about half of the volume of the entire high voltage generator, and the occupied area of the X-ray high voltage apparatus is It was huge.

In recent years, from the viewpoint of reducing the exposure dose during X-ray fluoroscopy, an X-ray high-voltage device having a pulse X-ray output function of generating pulsed X-rays in synchronization with the capture of a digital image has been required. However, the big 3
In a structure having a high-voltage switch for contacts, it is difficult to incorporate a grid control circuit for obtaining pulsed X-rays into a high-voltage generating circuit. This grid control circuit turns on and off X-rays by changing the voltage of the grid terminal to perform irradiation and stop.

For this reason, conventionally, a dedicated grid control circuit has been provided in addition to the X-ray high voltage device shown in FIG. When the conventional external grid control circuit is to be connected to an X-ray high-voltage device having an X-ray tube having three contacts on the cathode side, the grid control circuit has a negative side due to its nature. Because you need to connect,
On the wiring, three wires are connected to the minus side of the high-voltage switch, and a total of four wires are connected to the grid of the X-ray tube and three terminals on the cathode side, and the output from the minus side of the high-voltage switch is once sent to the grid control circuit. The wiring structure is such that an input is made and connected to the X-ray tube via the grid control circuit.

As described above, since the minus side of the X-ray tube has three contacts, it is complicated to incorporate a grid control circuit into the grid control circuit.

In particular, an X-ray high-voltage device having a pulse X-ray output function is large and expensive, and has been used only for circulatory diagnosis in large hospitals.

The present invention has been made in view of the above circumstances, and has as its object to reduce the size of a high-voltage switch and incorporate a grid control circuit, thereby saving space and inexpensive pulse X-rays. An object of the present invention is to provide an X-ray high-voltage device that can handle output.

[0028]

In order to achieve the above object, according to the first aspect of the present invention, a high voltage generating means for generating a high voltage and a high voltage output by the high voltage generating means are provided. An X-ray high-voltage device connected to a plurality of X-ray tubes that emit X-rays, the plurality of filaments being provided for each of the plurality of X-ray tubes and heating each of the X-ray tubes. A heating transformer and the high-voltage output are connected to a plurality of each of the Xs.
A first switching means for switching for each wire tube, and a second switching means provided on a primary side of the plurality of filament heating transformers for switching the plurality of filament heating transformers in accordance with the switching of the first switching means. Switching means.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of the preferred embodiment of the present invention will be specifically described with reference to the accompanying drawings.

First Embodiment (Overall Configuration) First, the configuration of the X-ray high-voltage device of the present invention will be described with reference to FIG. FIG. 1 is a block circuit diagram showing an embodiment of an X-ray high voltage device according to the present invention. However, the same parts as those in the conventional example will be described using the same reference numerals.

The difference between the present embodiment and the conventional example is that
A filament heating transformer is provided for each X-ray tube.
The filament heating output supplied to the tube is switched on the primary coil side of the filament heating transformer, and one of the two connected X-ray tubes is a triode X-ray tube with a grid. That is, a grid control circuit was added to control the pole tube.

As shown in FIG. 1, the X-ray high-voltage apparatus 1 of this embodiment comprises a commercial AC power supply 3, a rectifying and smoothing circuit (AC / DC) 5 for rectifying and smoothing the commercial AC power supply 3 and outputting a DC voltage. Inverter circuit that converts DC voltage to AC voltage (DC / A
C) 7, a high-voltage transformer 9 for converting an AC voltage into a predetermined high voltage, and a high-voltage rectifier circuit 11a for rectifying a high AC voltage.
11b, a three-pole X-ray tube 12a including an anode (A), a cathode (K), and a grid (G), and stray capacitances 15a, 15b, and 15 of high-voltage cables connected to the X-ray tube 12a.
e, a grid control circuit 16 for stabilizing the grid of the X-ray tube 12a, a bipolar X-ray tube 12b including an anode (A) and a cathode (K), and a stray capacitance 15c of a high-voltage cable connected to the X-ray tube 12b. 15d, filament heating transformers 21a and 21b provided for the X-ray tube 12a,
The filament heating transformers 21c and 21d provided for the X-ray tube 12b, the high-pressure switches 24a and 24b for selecting the X-ray tubes 12a and 12b, and the filament heating transformers 21a, 21b, 21c, and 21d are provided on the primary side. And a control circuit 17 for controlling the filament heating output destination switching switch 25, the filament heating circuit 23, and the inverter 7 based on the filament heating signal a, and controlling the filament heating circuit 23 based on the inverter operation signal b. I have.

The "high-voltage switching device" of the present embodiment corresponds to the "first switching means" of the present invention, and the "relay" of the present embodiment corresponds to the "second switching means" of the present invention. Corresponding.

The output of the filament heating circuit 23 is connected to two filament heating transformers 21a and 21b.

Since the relay 25 does not require high-voltage insulation on the low-voltage side, a relay that can be mounted on a normal PC board can be used.

In this embodiment, the X-ray tube 12a (first tube) and the X-ray tube 12b (second tube) can be used by one X-ray high-voltage device. It can also be used by medical practitioners and can be purchased by medical practitioners.

When two X-ray tubes are used for one X-ray high-voltage device, the X-ray tube 12a (first bulb) is used for diagnosis of the digestive tract (for example, for examination of the esophagus, stomach, large intestine, etc.). It is preferable to use the X-ray tube 12b (second tube) for general radiography (for example, for imaging a chest from behind). The first reason is that the X-ray tube 12a (first bulb) is attached to a support member on the bed together with an X-ray film transport mechanism, an optical system, an image system, etc. on an X-ray TV bed or the like. It is built so that
This is because it is usually difficult to use for other purposes other than the purpose dedicated to gastrointestinal diagnosis. The second reason is that in order to find a small affected area such as an early gastric cancer or a gastric ulcer, it is necessary to use a dedicated X-ray tube capable of taking a detailed image.

In the gastrointestinal tract diagnosis, it is necessary to alternately perform X-ray fluoroscopy and X-ray imaging in order to determine the imaging location and determine the imaging timing while observing the state of the contrast agent. In such a case, when viewing a fluoroscopic image on a monitor or the like, a pulse X-ray output function for outputting a moving image by outputting a weak X-ray pulse from the viewpoint of reducing the X-ray exposure dose of the subject and improving the fluoroscopic image quality. It is preferable to perform fluoroscopy with pulsed X-rays using an X-ray high-voltage device having the following. Therefore, the X-ray tube 12a
When performing X-ray fluoroscopy using the (first tube), grid control is required.

On the other hand, the other X-ray tube 12b (second tube) used for photographing the lungs, for example, generally has a configuration in which it is hung from the ceiling. In this case, the image is taken immediately after the positioning is performed, and the working voltage is high. In addition, when imaging the lungs and the like, it is necessary to shorten the imaging time to some extent in order to prevent the influence of the heartbeat.

(Operation) Next, the basic operation of the X-ray high-voltage device having the above configuration will be described with reference to FIG. The basic operation is the same as in the example shown in FIG. 6, and the same components are denoted by the same reference numerals.

The mechanism for obtaining a high voltage from the AC power supply 3 is the same as that of the conventional apparatus. The AC obtained from the commercial AC power supply 3 is converted into DC by an AC / DC converter (rectifying / smoothing circuit) 5, and is converted into DC. Inverter circuit 7 which is a / AC conversion circuit
Is supplied to

Here, the switching of the X-ray tubes 12a and 12b is performed by an operation panel (operation panel) (not shown) of the X-ray high-voltage device 1.
Perform based on. Nochi, there is a selection operation part on the operation panel,
For example, when a gastrointestinal diagnosing button is pressed in accordance with the purpose of diagnosis, one X-ray tube 12a (first bulb) is selected, and when a general imaging button such as the lungs is pressed, the other X-ray tube 12a is pressed. 12b (second bulb) is selected.

Then, in response to an instruction from the operation unit, a tube selector (not shown) makes a selection. The tube selector may be arranged in the X-ray high voltage device or in the operation console.

First, the case where the X-ray tube 12a having a grid (G) terminal is used will be described. The high-pressure switch 24a is turned on and the high-pressure switch is turned on by a tube selector for selecting an X-ray tube (not shown). 24b is off. Further, the filament heating output switching relay 25 is turned off, and the output of the filament heating circuit 23 is output from the X-ray tube 12.
It is supplied to the a side.

In this state, when X-ray imaging is started, the primary coil of the high-voltage transformer 9 is excited by the operation of the inverter circuit 7 based on the inverter operation signal a from the control circuit 17. The boosted AC (high frequency) voltage induced in the secondary coil of the high-voltage transformer 9 has a high voltage rectification circuit 11a on the plus side and a high voltage rectification circuit 1 on the minus side.
At 1b, it is rectified to DC.

Since the high voltage switch 24a is on, the voltage rectified by the high voltage rectifier circuits 11a and 11b is
It is smoothed by the stray capacitances 15a and 15b of the high voltage cable (capacitors which are line capacitances of the high voltage cable) and applied between the anode A of the X-ray tube 12a and the common C of the cathode.

On the other hand, when the filament heating circuit 23 is activated based on the filament heating signal b of the control circuit 17, the filament heating output switching relay 25 is turned off.
1b is excited, and the AC voltage induced in the secondary coil of the transformer heats the filament of the X-ray tube 12a via the high-voltage switch 24a.

Based on the signal b of the control circuit 17, the selected focus side (large L
Or, the output of one side of the small S increases and the X-ray tube 12
The filament a is heated to a temperature that emits thermoelectrons.

Here, the small S and the large L indicate the size of the focal point. It is preferable to use a small focal point when observing a fluoroscopic image on a monitor and to use a large focal point when photographing on a film.

When the small S is selected, the electrons are focused on a narrow area on the target surface, so that the image becomes sharp. At this time, the X-ray dose is set to be weakly controlled so that the amount of electrons emitted is such that the target cannot be melted, and the imaging time is controlled to be long in order to obtain an appropriate density.

On the other hand, when the large L is selected, control is performed so that the area of the focal point is widened to increase the X-ray dose, and that imaging is performed in a short time. Thus, in the case of a moving subject, the effect of penumbra appears, but shooting can be performed with a short time, and blurred motion can be prevented.

The large L and small S are controlled by a large filament heating transformer (a reference numeral 21a for the X-ray tube 12a and a reference numeral 21c for the X-ray tube 12b) and a small filament heating transformer (the reference numeral 21c for the X-ray tube 12a). 2
In the 1b-X-ray tube 12b, either the large focal point or the small focal point is selectively controlled depending on which transformer is excited in the filament heating circuit 23 in the reference numeral 21d). In this case, the configuration may be such that switching is performed with a button on an operation console (operation panel), or the configuration may be such that selection is automatically performed when a shooting condition is selected. For example, it is preferable that the control be performed based on a focus control circuit shown in the drawing inside the X-ray high voltage device.

The control parameters are a combination of X-ray intensity, tube voltage and tube current, time, and the like. First, the apparatus automatically determines whether a small focus can be obtained according to the set imaging conditions. When the focus cannot be obtained, it is preferable to perform the control by setting the control parameters after performing a determination process such as using a large focus.

As described above, when a high voltage is applied between A and C of the X-ray tube 12a, thermoelectrons jump out of the filament of the X-ray tube 12a and collide with the anode, thereby causing X-rays.
A line is illuminated.

At this time, the grid voltage of the X-ray tube 12a (the voltage of the grid G with respect to the cathode K) is substantially zero, and a current flows through the X-ray tube 12a, so that the X-ray tube 12a is irradiated. That is, at the time of X-ray irradiation, g-c of the grid control circuit 16 is short-circuited (the operation of the grid control circuit 16 will be described later).

Next, when the operation of the inverter circuit 7 stops, the secondary voltage of the high-voltage transformer 9 becomes zero, so that the charges of the floating capacitors 15a and 15b are discharged through the X-ray tube 12a.

At this time, the stray capacitance 15e between the grid and the cathode of the high voltage cable on the negative side is equal to the stray capacitance 15e.
When the grid voltage of the X-ray tube 12a reaches the cutoff voltage due to the discharge currents a and 15b, no current flows between the anode and the cathode of the X-ray tube 12a, and the X-ray irradiation stops. Thus, by starting and stopping the inverter circuit 7, the grid voltage of the X-ray tube 12a changes between zero and the cutoff voltage, and the current of the X-ray tube 12a can be turned on / off. As a result, a pulse current flows through the X-ray tube.
A line is illuminated.

On the other hand, when the X-ray tube 12b is used, the high voltage switch 24a is turned off and the high voltage switch 24b is turned on. Further, a relay 25 for switching the filament heating output is provided.
Is turned on, and the output of the filament heating circuit 23 is X
It is supplied to the wire tube 12b side.

In the same manner as described above, based on the filament heating signal b of the control circuit 17, the filament heating circuit 23
Selected focal side (L (Large) or S (Small)
Is increased, and the filament of the X-ray tube 12b is heated to a temperature at which thermoelectrons are emitted.

When the inverter circuit 7 operates based on the inverter operation signal a of the control circuit 17, the high voltage induced in the secondary coil of the high-voltage transformer 9 is rectified by the high-voltage rectification circuits 11a and 11b, Is applied between the anode A of the X-ray tube 12b and the common C of the cathode.

When a high voltage is applied between A and C of the X-ray tube 12b, thermoelectrons jump out of the filament of the X-ray tube 12b and collide with the anode, so that X-rays are emitted.

Here, in the conventional device, since the voltage is low, the contact resistance of the contact affects the performance of the circuit and the device. If the contact resistance is unstable, the current of the filament changes, and the tube current decreases. Accuracy is reduced, and stability is required on the order of, for example, 10 mΩ. Opening and closing with such a low voltage and a large current is mechanically large, and the contact pressure must be increased, which is difficult.

On the other hand, in the present embodiment, the switching portion is arranged on the primary side of the filament heating transformer by adopting the circuit structure shown in FIG. This allows
The part that needs to be switched on the high voltage side is only one contact on the positive side and one contact on the negative side, and it is no longer necessary to avoid a large current at the contacts of the high voltage switch. Thus, for example, if the high voltage tolerance, the flowing current is small (for example, 10 to 75 kV, 0.1 to 1000 mA, etc.),
The requirements for contact stability are reduced, and contacts of much smaller size are required.

(Grid Control) Next, in the X-ray tube 12a,
The operation of generating a pulse X-ray will be described below.

The X-ray tube 12a is a three-pole X having a grid.
When a high voltage is applied between the anode A and the common C of the cathode and the voltage between the grid G and the common C of the cathode is reduced to zero, thermions jump out of the filament and collide with the anode, thereby causing X-rays. Generate a line.

When a negative voltage is applied to the grid G with respect to the cathode common C, the number of thermoelectrons emitted from the filament decreases. When the negative voltage applied to the grid G is increased (increased in the negative direction),
Eventually, a cutoff state is reached in which no electrons are emitted. The voltage at this time is called a cutoff voltage. That is, a normal cutoff voltage is applied to the grid G of the X-ray tube 12a, and the grid G is applied at the timing of X-ray irradiation.
The pulse X-ray can be generated by giving a pulse in which the voltage of the X-ray becomes zero. Thus, by changing the voltage of the grid terminal, X-rays can be turned on and off to perform exposure and stop.

As the grid control circuit 16 in the example of FIG. 1, it is preferable to use a self-bias type grid control circuit disclosed in, for example, Japanese Patent Application Laid-Open No. 11-204289 by the present applicant. According to this method, a power supply for generating the grid bias voltage is not required,
The grid control circuit can be configured in a very simple way.

By performing grid control, X
When a moving image is viewed by X-ray diagnosis, X-rays may be output only when image data is collected by using a pulse for collecting the moving image. As a result, the exposure dose can be reduced and the size can be reduced.

As described above, in addition to the downsizing of the apparatus due to the reduction in the number of contacts of the high-voltage switch, the number of contacts on the minus side is one.
Since it has only the structure, the grid control circuit can be easily incorporated in the X-ray high-voltage device by simple wiring. Thus, when the X-ray tube has the common terminal C, the large terminal L, and the small terminal S as in the related art, it is not necessary to separately provide a dedicated grid control circuit (device). The apparatus can be made compact, the installation area is small, the cost can be reduced, and benefits can be obtained even in general practitioners and clinics.

(High Pressure Switch) Next, a high voltage switch used in the above-mentioned X-ray high voltage device will be described.
FIG. 2 discloses a structural example of a high-voltage switch in the X-ray high-voltage device of FIG. In the X-ray high-voltage device of this example, the circuit configuration is one because it is not necessary to switch the filament heating current on the secondary side of the filament heating transformer due to its circuit configuration.
A contact is sufficient, and the current capacity can be as small as 0.1 mA to 1 A.

Further, the structure of the high-voltage switch 101 itself is characterized in that the movable contact 104 is turned on and off by inserting and removing an insulating plate 105 as shown in FIG.

Specifically, as shown in FIG. 2, the high-voltage switch 101 includes a fixed contact 106 formed below the high-voltage socket 102, a movable contact 104 that can contact the fixed contact 106, and a fixed contact 106. Plate 105 (“insulating means” of the present invention) inserted between the movable contact 104 and the movable contact 104, a support member 103 supporting the insulating plate 105 and the movable contact 104, and moving the insulating plate 105 in the direction of the arrow. 112 and a biasing member 111 for biasing the insulating plate 105.

When the high-voltage switch 101 is on,
By the solenoid 112, the insulating plate 105 slides in the direction of the arrow in FIG. 2 and is pulled out with respect to the support member 103, the urging member 111 is extended, the insulating plate 105 is retracted, and the movable contact 104 is moved. The state comes into contact with the fixed contact 106.

On the other hand, when the high-voltage switch 101 is off, the urging member 111 is contracted by the solenoid 112, and the insulating plate 105 is inserted between the movable contact 104 and the fixed contact 106.

As described above, in the high-voltage switch used in the X-ray high-voltage device of this embodiment, the movable contact 104,
By adopting a structure in which the insulating plate 105 is inserted between the fixed contacts 106, the structure can prevent discharge even if the movable contact does not protrude.
06 can be shortened, and the high-pressure switch 101 can be further miniaturized.

As described above, according to the present embodiment, only one contact for switching the high voltage is required, and an insulating plate is inserted between the contacts when the high-voltage switch is opened (off). As a result, the distance between the contacts can be reduced, the high-voltage switch can be significantly reduced in size, and the grid control circuit can be easily incorporated.

Further, it is an object of the present invention to provide an X-ray high-voltage device which is small and can be connected to a plurality of X-ray tubes, and can be used for both a bipolar X-ray tube and a triode X-ray tube for generating pulsed X-rays. Can be. As a result, the cost of digital machines, which were expensive for large hospitals, can be reduced, and it can be easily introduced in small hospitals such as general practitioners, contributing to the low exposure of patients and subjects to X-rays. it can.

Since the filament heating transformer is provided for each X-ray tube, the number of filament heating transformers used is larger than before, but there is no problem since the filament heating transformer can be downsized by the inverter technology. .

[Second Embodiment] Next, a second embodiment according to the present invention will be described with reference to FIG. In the following, description of substantially the same configuration of the first embodiment will be omitted, and only different portions will be described. FIG. 3 discloses a modification of the high-pressure switch.

In the high-voltage switch of the first embodiment, the sliding direction of the insulating plate is set to a direction intersecting the axis of the high-voltage socket. In the high-voltage switch of the present embodiment, the sliding direction of the insulating plate is changed to the socket. Are formed in parallel with the axial direction of.

Specifically, as shown in FIG. 3, the high voltage switch 120 includes a fixed contact 121 provided below the high voltage socket 122, a movable contact 124 that can contact the fixed contact 121, Sliding movement and movable contact 124
An insulating plate 125 for preventing contact with the fixed contact 121,
Support member 1 supporting insulating plate 125 and fixed contact 121
23, an urging member 126 for urging the movable contact 124,
It is comprised including. The mechanism for inserting and removing the insulating plate 125 is not limited to a solenoid.

When the high voltage switch 120 is on,
The insulating plate 125 is pulled out of the supporting member 123 by the sliding movement in the direction of the arrow in FIG. 3 by the solenoid for sliding the insulating plate (not shown), and the movable contact 124 urged by the urging member 126 is turned into the fixed contact 121. And comes into contact with it.

On the other hand, when the high-voltage switch 120 is in the off state, the movable contact 124 is retracted by the movable contact moving solenoid (not shown), while the insulating plate 125 is moved by the not-shown insulating plate sliding solenoid. By sliding in the direction, the contact of the movable contact 124 with the fixed contact 121 is avoided.

As described above, also in the present embodiment, the space between the movable contact 124 and the fixed contact 121 can be reduced by inserting the insulating plate 125 between the movable contact 124 and the fixed contact 121 when the circuit is opened. Therefore, the size of the high-pressure switch 120 can be reduced.

Further, the space required for the sliding movement of the insulating plate 125 is constituted by utilizing the space in the axial direction of the high-pressure socket 122, thereby further reducing the size of the high-pressure switch disclosed in the first embodiment. Becomes possible.

[Third Embodiment] Next, a third embodiment according to the present invention will be described with reference to FIGS. FIGS. 4A to 4C show an example of a high-pressure socket for the cathode side of an X-ray tube used in the X-ray high-voltage device of the present invention, and a plug corresponding thereto.

As shown in FIGS. 4A and 4B, X in this example
In a high-voltage socket 202 used for the line high-voltage device 201, a large terminal L, a small terminal S, and a common terminal C arranged in a substantially annular cross section, and a grid terminal G arranged substantially in the center of the ring are formed. Have been.

The large terminal L of the high voltage socket 202 and the plug 203 inserted into the high voltage socket 202
A large terminal L, a small terminal S, a common terminal C, and a grid terminal G of a plug 203 that are respectively inserted into the small terminal S, the common terminal C, and the grid terminal G are formed.

As shown in FIG. 4B, the arrangement positions of the terminals of the high voltage socket 202 are as follows: large terminal L, small terminal S, common terminal C with grid terminal G as the center.
Are arranged annularly at intervals of approximately 120 degrees.

Here, generally, the structure of the high-pressure socket has a structure as shown in FIGS. 8A and 8B, and is a high-voltage socket 50 of a two-pole X-ray tube having no grid terminal.
In FIG. 5, as shown in FIG. 8A, a common terminal C, a small terminal S, and a large terminal L are arranged in a substantially annular cross section. Further, as shown in FIG. 8B, the high-voltage socket 506 of the X-ray tube for a triode having a grid terminal is configured such that the common terminal C, the small terminal S, and the large terminal L are separated from the grid terminal G. It is arranged. Thus, 3
The high-voltage socket 506 of the X-ray tube for the pole and the high-pressure socket 505 of the X-ray tube for the bipolar have different structures. In this case, the high voltage socket 505 for 3 pins and the high voltage socket 506 for 4 pins are not compatible, so that one bed uses an X-ray tube without a grid and the other bed has a grid. In the case of using an X-ray tube of the type, a normal dipole X-ray tube and a pulse X
When a triode X-ray tube used for line output is used, the number of poles of a high-voltage cable used on the cathode side is different, so that a dipole X-ray tube and a triode X-ray tube are used. It is necessary to provide a dedicated high-pressure socket for each.

On the other hand, in the present embodiment, the high-voltage socket has a structure as shown in FIG. Even with an X-ray tube, insertion and removal can be performed freely. There is no need to prepare high-pressure sockets for each type of X-ray tube, and one type of high-pressure socket can be used for both types of X-ray tubes (diode and triode). Type of X-ray tube.

Here, the voltage connected to the common terminal C, the large terminal L, and the small terminal S is as low as, for example, about 20 V, so that there is no problem even if the distance is short and they are arranged on a plane. However, the grid terminal G for blocking X-rays has, for example, -1000 to-
Since a negative high voltage such as 3000 V has to be applied, it is necessary to physically separate the grid terminal G from the other three terminals.

Therefore, in this example, as shown in FIG. 4A, at the base end where the grid terminal G protrudes from the resin, a projection (step) is formed to secure the distance along the creepage. I have. Therefore, even if the distance between the grid terminal G and each of the other terminals C, S, and L on the plane is formed as narrow as T2, actually, T2 + T1 including the distance corresponding to the height T2 at which the resin rises. By forming a distance, discharge or the like at the time of high voltage can be prevented.

As described above, according to the present embodiment, the common, large, and small terminals of the high-voltage socket are arranged in a substantially annular cross section, and the terminal arrangement is such that a grid terminal is formed at the center of the ring. By doing so, the X-ray tube for 2 poles, 3 poles X
A high-pressure socket can be used for both of the wire tubes. Moreover, at this time, by forming a convex portion around the protruding base end of the grid terminal, a distance between terminals between each terminal and the grid terminal can be secured, and no discharge or the like occurs even when a high voltage is applied. .

Although the apparatus and method according to the present invention have been described according to some specific embodiments thereof,
Those skilled in the art various modifications are possible with respect to the embodiments described in the body of the present invention without departing from the spirit and scope of the present invention. For example, in each of the above embodiments, the X-ray high-voltage device has a two-tube structure including a three-pole X-ray tube having a grid terminal and a two-pole X-ray tube having no grid terminal. An X-ray high-voltage device having a tube, for example, a three-tube structure may be configured. In this case, it is preferable to form a triode X-ray tube having a grid terminal as a first tube and a dipole X-ray tube without a grid terminal as a second tube and a third tube.

Also, a configuration in which the cathode side of a three-pole X-ray tube having a grid terminal has common, large, and small terminals has been disclosed. X which is a configuration of only
It may be a wire tube. Of course, the same can be said for a two-pole X-ray tube having no grid terminal.

Further, an example of a combination of each of the above-described embodiments and any one of them and a modification (for example, in the X-ray high-voltage device of the first embodiment, the high-voltage switch of the second embodiment) And the case of having the structure of the high-pressure socket of the third embodiment).

[0098]

As described above, according to the present invention, a filament heating transformer is provided for each of a plurality of X-ray tubes, and in addition to the first switching means for switching the plurality of X-ray tubes, each of the X-ray tubes is provided.
The filament heating output to be supplied to the wire tube is switched by the second switching means on the primary side of the filament heating transformer.

As a result, the second switching means for switching on the low voltage side (primary side) is constituted, so that the parts which need to be switched by the first switching means on the high voltage side (secondary side) , The X-ray tube has only one contact on each of the positive side and the negative side, so that the number of contacts on the high voltage side (secondary side) can be reduced, and the high voltage side has a high voltage and low current.

Therefore, even if the pressure is high, the requirement for the stability of the contact of the first switching means is reduced, and a contact having a considerably small size is required. As a result, the X-ray height is reduced due to the downsizing of the first switching means. The size and cost of the voltage device can be reduced.

Further, since the insulating means is interposed between the contacts when the first switching means is opened, the distance between the contacts can be shortened even at a high voltage. The size of the switching means can be greatly reduced.

Further, when at least one of the X-ray tubes is constituted by an X-ray tube having a grid terminal by reducing the number of contacts of the first switching means on the high voltage side, the grid control circuit can be simplified. It can be built in the wiring structure, and it can reduce the price of expensive digital machines for large hospitals, so it can be easily introduced even in small hospitals such as general practitioners, and patients and patients It can contribute to X-ray exposed low frequencies.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an embodiment of an X-ray high voltage device according to the present invention.

FIG. 2 is a structural diagram showing an example of an embodiment of a high-voltage switch used in the X-ray high-voltage device of FIG.

FIG. 3 is a structural diagram showing another embodiment of the high-voltage switch used in the X-ray high-voltage device of the present invention.

FIGS. 4A to 4C are structural views showing an example of an embodiment of a cathode-side high-pressure socket of an X-ray tube used in an X-ray high-voltage device of the present invention.

FIG. 5 is a basic block diagram showing a configuration example of a conventional X-ray high-voltage device.

FIG. 6 is a basic block diagram showing a configuration example of a conventional X-ray high-voltage device for connecting two X-ray tubes.

FIGS. 7A and 7B are structural diagrams of a high-voltage switch used in a conventional X-ray high-voltage device.

FIGS. 8A and 8B are structural views showing a high-pressure socket of an X-ray tube used in an X-ray high-voltage device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 X-ray high voltage apparatus 3 AC power supply 5 Rectifier smoothing circuit 7 Inverter circuit 9 High voltage transformer 11a, 11b High voltage rectifier circuit 12a, 12b X-ray tube 15a, 15b, 15c, 15d, 15e Floating capacity 16 Grid control circuit 17 Control circuit 21a, 21b, 21c, 21d Filament heating transformer 23 Filament heating circuit 24a, 24b High voltage switch 25 Relay 202 High voltage socket

Claims (4)

[Claims] 1. High voltage generating means for generating a high voltage;
An X-ray high-voltage device connected to a plurality of X-ray tubes that emit X-rays based on a high-voltage output from the high-voltage generating unit, wherein the X-ray tubes are provided for each of the plurality of X-ray tubes. A plurality of filament heating transformers for heating each of the X-ray tubes, and a first for switching the high voltage output for each of the plurality of X-ray tubes
Switching means, provided on the primary side of the plurality of filament heating transformers, and connecting the plurality of filament heating transformers to the first
And a second switching means for switching in accordance with the switching of the switching means. 2. The apparatus according to claim 1, wherein said first switching means includes an insulating means for insulating between respective contacts to be opened and closed.
2. The X-ray high voltage device according to 1. 3. The at least one X-ray tube is formed of a triode X-ray tube having an anode terminal, a cathode terminal, and a grid terminal for controlling a grid, and a grid terminal of the triode X-ray tube is provided. 3. The X-ray high-voltage device according to claim 1, further comprising a grid control circuit configured to control the high-voltage X-ray. 4. The at least one X-ray tube includes an anode terminal formed on the anode side, a common terminal, a large terminal, and a small terminal formed on the cathode side, and a grid terminal for grid control. The high-voltage socket for connecting a cable wired to the cathode side of the X-ray tube includes the common terminal, the large terminal,
The X-ray high-voltage device according to claim 3, wherein each terminal corresponding to the small terminal is disposed substantially in a ring shape, and a terminal corresponding to the grid terminal is disposed in a center portion of the ring. .